1. Field of the Invention
Generally speaking, the invention relates to linear LED lighting, and more particularly, to linear LED lighting with on-board light guides.
2. Description of Related Art
Over the last decade, lighting based on light-emitting diodes (LEDs) has become dominant in the lighting industry, and is widely used in both residential and commercial installations. LED-based lighting has a number of advantages compared with legacy incandescent and fluorescent lighting, including high efficiency and low power draw, relatively low operating temperatures, and, with some models, selectable color and controllable color temperature.
For most commercial and residential applications, two major types of LED-based lighting are used: bulb-type lamps and linear lighting. Bulb-type lamps are intended as direct replacements for incandescent light bulbs, typically have a shape similar to the type of bulb they are intended to replace, have a traditional socket to connect to a fixture and draw power, and are usually constructed to produce roughly the same light output as the bulbs they are intended to replace. Linear lighting is somewhat different—it usually includes a number of LEDs arranged at a regular spacing or pitch along a printed circuit board (PCB). That PCB may be rigid, made, for example, of FR4 composite, or it may be flexible, made, for example, of Mylar. In either case, the PCB usually has the form of a thin strip, although other shapes and sizes are possible. The amount of light produced by a strip of linear lighting depends on the properties of each LED, the pitch of the LEDs, and the total length of the strip, and is usually expressed in units of light intensity per unit length.
One of the major advantages of linear lighting is its versatility. Alone, it can serve as accent lighting or task lighting, often in locations where it would be difficult to install traditional lighting fixtures. Placed in an appropriate extrusion and covered with a diffuser, it can serve as primary room lighting, replacing legacy fluorescent fixtures in offices. Properly electrically insulated and encapsulated, it can be used even in outdoor and wet locations.
Despite myriad advantages, linear lighting does have some drawbacks. For example, unmodified, the light from a strip of linear lighting appears as a number of discrete points of light. This is acceptable for many applications, but not all. The usual solution is to place the lighting in an extrusion and cover it with a diffuser, which, again, is acceptable for many applications, but not all.